轮南地区奥陶系碳酸盐岩古岩溶特征

泥盆纪末期的早海西运动及二叠纪末的晚海西运动, 均使塔里木盆地轮南地区抬升而遭受风化剥蚀, 奥陶系出露地表遭受大气淡水的淋滤、溶蚀作用, 形成潜山。轮南地区岩溶系统发育, 大多数井在奥陶系钻有缝洞系统, 发育的层位为一间房组、鹰山组的灰岩内。岩溶、构造作用是控制奥陶系储集层分布的重要因素。研究表明, 垂向上储集层主要发育在风化壳300 m 范围内。平面上地表岩溶作用发育于轮南地区中部、西部, 储集空间为裂缝、溶孔、溶洞; 东部主要受构造作用影响, 储集空间主要为裂缝。     

塔北地区原油碳同位素组成特征及影响因素

以塔里木盆地轮南地区与哈得逊地区20个原油样品的全油碳同位素组成和正构烷烃单体烃碳同位素组成分析为基础,结合油源、区域构造演化以及成藏过程的研究,探讨影响原油碳同位素特征的主要因素.研究表明,轮南地区原油的全油碳同位素组成值均大于-32‰,而哈得逊地区原油的全油碳同位素组成值一般小于-32‰;原油正构烷烃单体烃碳同位素组成也表现出轮南地区重于哈得逊地区的特征.两地区原油碳同位素组成的这种特征是由于两地区油气成藏过程的差异造成的,轮南地区原油碳同位素组成比哈得逊地区的原油碳同位素组成重的主要原因是轮南地区原油中混入了来源于寒武系的降解原油,而非二者油源不同造成.图6表2参11     

轮南地区奥陶系断裂及储集层裂缝分形特征

应用分形理论，对塔里木盆地北部轮南地区奥陶系断裂及储集层裂缝进行研究，结果表明，该区的断裂及储集层裂缝分布均具分形结构，自相关性很好，其相关系数均大于０９９进一步研究表明，平面上的断裂发育区和井下的储集层裂缝发育带是对应的。在碳酸盐岩中找油，储集条件是关键。因此，要彻底弄清轮南奥陶系含油性，应从储集层条件最好的地方入手。分形研究证明，整个轮南地区储集层最好的是平台西区，这应成为近期油气勘探的首选区块。     

塔里木盆地轮南油田三叠系砂岩储层土酸酸化增注工艺技术

通过对轮南油田三叠系砂岩储层特征和试井资料分析,提出用土酸酸化进行增注的措施,取得显著效果。     

塔里木盆地原油碳硫同位素特征及油源对比

以碳、硫同位素在石油生成演化过程中的分馏作用为基础,对塔里木盆地原油、油源对比进行了探讨。原油的δ¹³C继承了生物母质的δ¹³C值,海相原油的δ¹³C小于-32‰或大于-24‰,陆相原油的δ¹³C为-32‰~-24‰。原油中有机硫来源于源岩中的硫酸盐,温度高于成熟原油(80~120℃)的δ³⁴S与油源岩中硫酸盐的δ³⁴S接近,但原油δ³⁴S似要比相应的硫酸盐δ³⁴S轻3‰~4‰。根据碳、硫同位素特征和原油其它物理化学特性可以将塔里木盆地原油分为4种。第1种为寒武—奥陶纪原油,其δ³⁴S为21‰~26‰,δ¹³C小于-32‰,为典型的海相原油,并可细分为寒武纪原油(δ³⁴S在24‰~26‰)和奥陶纪原油(δ³⁴S为21‰~22‰)。第2种为石炭—二叠纪原油,其δ³⁴S为5‰~7‰,δ¹³C小于-32‰,亦为海相原油,如沙3井原油,但母质类型较差。第3种为三叠—侏罗纪原油,δ³⁴S在10‰~14‰,δ¹³C在-26‰左右,为典型的陆相原油。第4种则是前3种原油的混合相原油,δ³⁴S介于海相原油与陆相原油之间,-C—O和C—P两种海相原油混合,其物理化学性质仍为海相原油特征,而-C—O与T—J原油混合则具有混合相原油的性质,没有发现C—P原油与T—J原油的混合油。     

塔里木盆地轮南油田油源分析及勘探前景

综合研究了轮南地区原油的地球化学特征,结合构造发育史、烃源岩演化史和油气分布特征,认为轮南地区原油主要来源于寒武系–下奥陶统烃源岩,并指出塔里木盆地的油气勘探应该主要集中到以寒武系– 下奥陶统为主要烃源岩的战略目标上来,在轮南地区寄希望于中– 上奥陶统为烃源岩来寻找大油田是不可思议的,必将引起对勘探的误导。     

塔里木盆地轮南—塔河奥陶系油田发现史的回顾与展望

塔里木盆地轮南和塔河奥陶系潜山风化壳碳酸盐岩油气藏具有相同的油气分布、储层特征、油藏类型和成藏条件,纵横向联成一体,同属于一个大油田。塔里木盆地奥陶系油气藏的发现井是轮南1井,以后经历了艰苦的探索过程,1996年取得了重大突破。从单井高产到获得探明储量,主要依靠一整套先进的地球物理、钻井、测井和测试技术。预计近几年内,轮南一塔河奥陶系油田将向东、西、南3个方向不断扩展,探明储量很快将达到10×10⁸t以上,可采储量达到1×10⁸t。     

轮南油田三叠系油藏气举采油的选择及应用──兼与窦宏恩同志讨论

轮南油田三叠系油藏机械采油方式自1991年决定采用气举以来,目前已建成压气站一座,有20余口井投入气举采油,而且生产正常。但有人对此提出了不同意见,认为该地区的机械采油应首选水力活塞泵。针对这一问题,本文重申了该油藏的机械采油设计原则,论述了利用油井供排协调原理预测机采井生产可行性的基本方法,由此得出的气举参数与现场实际生产数据相吻合。同时分析了该油藏选择气举采油的主要依据,对气举和水力活塞泵采油在该油藏的适应性进行了对比分析,澄清了气举测试工艺、注气压力设计等有关问题,并对进一步提高该油藏的气举开采提出     

轮南油田三叠系油藏采油方式的选择

轮南油田三叠系油藏是新疆塔里木油区即将正式投入开发的第一个油藏,它地处沙漠、交通不便、气候条件差,对油井自喷期过后采油方式的选择要求具有设备简单、工作可靠、免修期长、管理人员少等特点。根据该油藏的储层特征、井筒状况、流体性质、地理位置、能源供应等实际条件,结合当前采油工艺的发展水平及举升设备的能力,应用计算机对不同采油方式的可行性及适应性进行了系统的分析对比,优选结果认为气举为该油藏油井自喷期之后的最佳机械采油方式。     

轮南油田三叠系油藏连通性的地球化学研究

塔里木盆地轮南油田三叠系原油是来自下古生界源岩的成熟海相原油,原油的物理性质和地球化学性质都十分相似,用总的特性很难区分不同油藏的原油.用原油气相色谱指纹法对轮南油田2、3井区三叠系油藏的连续性进行了研究,并与早期研究的结论进行了对比.结果表明,这种方法是评价油藏原油连续性的一种有效手段,它的应用有助于对油藏构造形态的深入了解,并能为油藏早期开发方案的设计提供辅助性依据.     

原油单体烃类的碳同位素组成研究

本文利用新兴的原油单体烃类在线同位素分析技术测定了塔里木盆地原油及凝析油的正构烷烃、轻烃部分的异构烷烃和植烷、姥鲛烷的稳定碳同位素值，根据原油单体烃的碳同位素分布，并结合地质情况，将塔里木盆地原油分为源于下古生界，上古生界，中新生界和上述源岩混源的４种成因类型，并确认塔里木盆地是一个以下古生界油源为主的多油源的复合含油气盆地。本文还对原油单体烃碳同位素分布特征及成因等问题进行了初步探讨。     

BIOMARKER GEOCHEMISTRY OF CRUDE OILS FROM THE QAIDAM BASIN, NW CHINA

A suite of 16 crude oil samples from 13 oilfields in the Qaidam Basin were analyzed using techniques including gas chromatography and gas chromatography - mass spectrometry. Biomarker compositions and parameters were used to investigate the palaeoenvironmental and depositional conditions and to correlate the oils with eachother. Oils from the western Qaidam Basin have pristane/phytane (Pr/Ph) ratios of less than 0.7, and contain abundant gammacerane, C₂₇ steranes, 4-methyl steranes and long-chain tricyclic terpanes. C₂₉ sterane 20S/(20S+20R) and ββ/(ββ+αα) ratios show that the western Qaidam oils have variable maturities ranging from immature to mature. Oils from the northern Qaidam Basin, by contrast, have Pr/Ph ratios greater than 3, low gammacerane contents, and relatively abundant C₂₉ steranes, bicyclic terpanes and alkylcyclohexanes. C₂₉ sterane 20S/(20S+20R) and ββ/(ββ+αα) ratios indicate that the northern Qaidam oils are mature.
δ¹³C values, which range from -25.4‰ to -28.3‰ with the exception of one oil from the north (-3l.6‰), are similar for oils from both the northern and western parts of the Qaidam Basin. The oils'carbon isotope compositions are similar to those of the organic matter in potential source rocks.
The western Qaidam oils are inferred to have originated from Tertiary source rocks deposited under anoxic and saline-hypersaline lacustrine conditions with dominant algal organic matter. The northern Qaidam oils are interpreted to be derived from Jurassic source rocks which were deposited in a freshwater lacustrine environment and which are dominated by terrigenous organic matter.     

塔里木盆地塔河油田奥陶系碳酸盐岩成岩作用与孔隙演化

奥陶系是塔河油田最主要的产层,该文系统研究了碳酸盐岩成岩作用类型、成岩序列和成岩环境,分析了对储集性有重要影响的胶结作用、溶解作用、热水成岩作用和破裂作用,恢复了碳酸盐岩成岩和孔隙演化史,提出了储层形成的成岩依据.      

GEOCHEMICAL COMPOSITION OF ORDOVICIAN OILS FROM THE TUOPUTAI REGION,NORTHERN TARIM BASIN,NW CHINA: SOURCE ROCK CORRELATION

Molecular and stable carbon isotope compositions of 46 Ordovician crude oil samples from wells in the Tuoputai region of the northern Tarim Basin were investigated using GC–MS, MRM GC–MS and IRMS to determine their genetic relationships and to identify possible source rocks. Thirty-three source rock samples from outcrops and cores were also investigated. The oil samples varied from light to heavy crudes and showed very narrow δ¹³C value ranges for the whole oil, saturated and aromatic fractions. The majority of the oils displayed very similar molecular compositions with relatively high concentrations of n-alkanes and isoprenoids and low concentrations of terpenoids and steroids. Comparison of the compositions of these crude oils strongly suggested their genetic affinity, while maturity parameters indicated maturity variations from the peak to the late oil generation stages. The samples also showed the characteristics of mixtures of biodegraded and fresh oil charges. Bitumen extracts from Cambrian and Ordovician source rocks were studied in detail. The oil compositions suggested a marine marl source deposited in anoxic, hypersaline conditions with significant bacterial and algal organic matter inputs. The distributions of C₂₆–C₂₈ triaromatic steroids, tricyclic terpanes and regular steranes appear to have been greatly influenced by thermal maturation, making them unreliable for correlating the oils and the source rocks. In contrast, dinosteranes and triaromatic dinosteroids seem not to have been affected by maturation and were more useful for correlation studies. They indicated that there was no or little genetic relationship between the Cambrian – Lower Ordovician source rocks and the oils, but in general suggested a possible Middle – Upper Ordovician source for the oil accumulations in the Tuoputai field. However, the occurrence of triaromatic dinosteroids in oil from well TP28XCX may also suggest a minor contribution from Cambrian – Lower Ordovician source rocks.     

塔里木盆地塔河油田下奥陶统油藏特征及成藏条件分析

地质综合研究和勘探实践表明,塔河油田是在长期发育的古隆起基础上形成的下奥陶统碳酸盐岩岩溶-缝洞型大型油气田。该油田主力产层下奥陶统碳酸盐岩发育孔、洞、缝3类储集空间,组成裂缝型、孔洞-裂缝型、裂缝-孔洞型和生物礁(滩)相孔隙型4类储层。长期生烃、多期构造运动和多期岩溶作用使塔河油田不同区块原油性质有一定差异。下奥陶统油气聚集成藏主要受阿克库勒凸起、碳酸盐岩溶蚀孔洞缝发育程度和石炭系巴楚组泥岩覆盖等多种因素综合控制。     

A THIRD‐ORDER UNCONFORMITY WITHIN LOWER ORDOVICIAN CARBONATES IN THE TARIM BASIN,NW CHINA: IMPLICATIONS FOR RESERVOIR DEVELOPMENT

This paper presents outcrop, petrographic, geochemical, well log and seismic data which together characterise the third‐order T₇⁸ unconformity located between the carbonate‐dominated Lower Ordovician Penglaiba and Yingshan Formations in the Tarim Basin, NW China. Unconformities in Lower Palaeozoic carbonates in this basin are of increasing interest because major reserves of hydrocarbons have recently been discovered at the North Slope field (> 1000 × 10⁶ brls oil and ～ 3050× 10⁸ m³ gas). The reservoir here consists of karstified Lower Ordovician carbonates bounded by a third‐order unconformity. The T₇⁸ unconformity in Tarim Basin represents a short‐term exposure surface (< 1 Ma) controlled both by sea‐level changes and by palaeogeographic location within the basin, and the intensity of karstification varies laterally. The unconformity has had a major influence on porosity development in the underlying Penglaiba Formation carbonates. At two measured outcrop sections at the NW basin margin (Penglaiba and Shuinichang), dissolution porosity was observed in karstified and dolomitised carbonates below the T₇⁸ unconformity surface. A seismic profile shows the presence of reflection anomalies below the unconformity which are interpreted as karst‐related palaeo‐caverns. Geochemical data indicate that the T₇⁸ unconformity is associated with anomalies in stable isotope ratios and in heavy mineral and trace element profiles. Thus there are negative excursions in δ¹³C and δ¹⁸O ratios within the carbonate rocks immediately below the unconformity surface. Similarly, concentrations of major and trace elements such as Li, K, Ti, Rb, Th, Sr, V and Ni are significantly reduced in the underlying carbonates, while there is an anomalously high content of haematite‐limonite.     

塔里木盆地塔河油田下奥陶统碳酸盐岩的深埋溶蚀作用及其对储集体的影响

塔河油田下奥陶统碳酸盐储层主要受表生岩溶控制,但后期发育埋藏溶蚀作用,对原岩溶储层产生改造调整,埋藏溶蚀发育区增加了原储层的储渗能力并可能形成以孔隙为主导的储集类型,另一方面,与埋藏溶蚀相对的埋藏充填(胶结)发育区,使原储层储集性能降低,增强了原储层的非均质性.文章探讨了埋藏溶蚀的识别标志,形成机理,认为热对流循环是埋藏溶蚀-沉淀的动力学机制,据此研究了塔河油田地温场特征并初步探讨了埋藏溶蚀作用在塔河油田的分布规律.     

对准噶尔盆地东部彩南油田侏罗系油藏原油族(组)群类型的认识

彩南油田周围及外缘各凹陷内,不同程度地发育了石炭系、二叠系、三叠系以及侏罗系等生油层系,均发育有暗色泥岩。长期以来对彩南油田侏罗系油藏原油的来源没有定论。根据原油稳定碳同位素和生物标志化合物地球化学特征可以将研究区原油划分为5个族群,以彩南油田侏罗系油藏为主的第Ⅳ族群原油δ¹³C值分布在-27.9‰～-29.0‰之间,Pr/Ph值多数在2.5以上,生物标志物特征非常一致,该类原油在准东地区分布广泛,应该来源于中、下侏罗统煤系地层的湖相烃源岩,有机质类型为腐泥-腐殖混合型,而并非不同时代、不同有机相烃源岩生烃的混合产物。     

塔里木盆地塔河油田原油中双金刚烷分布特征与油气运移

研究了塔里木盆地塔河油田原油中双金刚烷的分布特征，探讨了该油田油气的充注期次和运移方向，结果表明，原油中双金刚烷指标值反映了原油的成熟度，并且指示研究区4区和6区原油充注时间较早、9区原油充注时间较晚，其它油区原油充注时间介于上述二者之间；原油中双金刚烷指标值分布特征显示出塔河油田下奥陶统油气存在2个充注方向，一是由南向北，并且油气成熟度相对较低，可能主要代表了早期的油气运移，另一个是由东向西，原油成熟度相对较高，可能主要代表了晚期的油气运移。根据原油成熟度和运移方向特征，认为塔河油田的早期油气起源于满加尔坳陷，晚期油气起源于满加尔坳陷和草湖坳陷，主力烃源岩层为寒武-奥陶系。